1. Field of the Invention
The present invention relates to a liquid crystal display device and, more particularly, to a stereoscopic liquid crystal display device having a touch panel and a method for manufacturing the same, wherein the liquid crystal display device includes a touch panel and an electrically-driven liquid crystal lens realizing a stereoscopic image, thereby being capable of performing a function of displaying stereoscopic images and touch detection.
2. Discussion of the Related Art
Recently, as the world has reached a full-scale information age, the field of display that can visually express electric information signals has developed at a vast rate. And, in order to meet with the requirements of such development, various types of flat display devices having excellent functions and characteristics, such as compact size, light weight, low power consumption rate, and so on, have been developed so replace the cathode ray tube (CRT) displays.
Detailed examples of such flat display devices may include liquid crystal display (LCD) devices, plasma display panel (PDP) devices, field emission display (FED) devices, electro-luminescence display (ELD) devices, and so on. More specifically, these flat display devices commonly include a flat display panel realizing images as an essential element. Herein, a flat display device has the structure of a pair of transparent insulation layers bonded so as to face into each other between unique light-emitting or polarization material layers.
Herein, the liquid crystal display device uses an electric field to adjust light transmissivity of the liquid crystals, thereby display an image. In order to do so, an image display device consists of a display panel having liquid crystal cells, and a driving circuit for driving a backlight unit and the liquid crystal cells, wherein the backlight unit emits light rays to the display panel.
The display panel is configured so that a plurality of gate lines and a plurality of data lines crossover one another, so as to define a plurality of unit pixel regions. At this point, each pixel region is provided with a thin film transistor array substrate and a color filter array substrate facing into each other, a spacer maintaining a predetermined cell gap between the thin film transistor array substrate and the color filter array substrate, and liquid crystal filling the cell gap.
A thin film transistor array substrate consists of gate lines and data lines, a thin film transistor formed as a switching device at each crossing point between the gate lines and the data lines, pixel electrodes formed in liquid crystal cell units and connected to the thin film transistor, and an alignment layer deposited thereon. Each of the gate lines and the data lines receives a signal from driving circuits through a pad unit.
The thin film transistor responds to a scan signal supplied to the gate line, so as to a supply pixel voltage signal, which is supplied to the data line, to the pixel electrode.
The color filter array substrate consists of color filters formed in liquid crystal cell units, a black matrix for identifying the color filters and for reflecting external light, common electrodes commonly supplying reference voltage to the liquid crystal cells, and an alignment layer deposited thereon.
Thereafter, the thin film transistor array substrate and the color filter array substrate that are separately configured, as described above, are aligned and bonded so as to face into each other. Subsequently, liquid crystal is injected between the two substrates, which are then sealed.
Recently, demands for adding a touch panel to the liquid crystal display device having the above-described structure have been increasing. Herein, the touch panel may recognize specific portions touched by the hand of the user or by a separate input means and may transmit separate information with respect to recognized portion of the screen (or panel).
Additionally, apart from the touch panel, the liquid crystal display device is also separately provided with a lenticular lens for displaying stereoscopic images.
Hereinafter, the related art stereoscopic liquid crystal display device having a touch panel fixed thereto will now be described in detail with reference to the accompanying drawing(s).
FIG. 1 illustrates a cross-sectional view showing a liquid crystal display device having a general touch panel fixed thereto.
Referring to FIG. 1, the liquid crystal display device having a general touch panel fixed thereto is sequentially provided with a liquid crystal panel 50, a lens layer 60, and a touch panel layer 70. The liquid crystal display device is also provided with a first adhesion layer 55 and a second adhesion layer 65 between each interface.
Herein, each of the first adhesion layer 55 and the second adhesion layer 65 corresponds to a double-sided adhesion layer respectively adhering (or bonding) the liquid crystal layer panel 50 to the lens layer 60 and the lens layer 60 to the touch panel layer 70.
Also, the liquid crystal panel 50 includes a first substrate 10 and a second substrate 20 facing into each other, a liquid crystal layer 25 filling the space between the first substrate 10 and the second substrate 20, a color filter layer 21 (21a, 21b, and 21c) formed on each surface of the second substrate 20 touching (or contacting) the liquid crystal layer 25, and a first polarizing layer 31 and a second polarizing layer 32 each formed on a rear surface of the first substrate 10 and the second substrate 20.
The lens layer 60 is placed above the liquid crystal panel 50, the first adhesion layer 55 being place between the lens layer 60 and the liquid crystal panel 50. Herein, the lens layer 60 includes a first plate layer 41, a lenticular lens array 45 having a lens function on the first plate 41, and a second plate layer 42 flattening the lenticular lens array 45.
Furthermore, the touch panel layer 70 is separately placed above the lens layer 60, the second adhesion layer 65 being placed between the touch panel layer 70 and the lens layer 60. Herein, the internal structure of the touch panel layer 70 may vary depending upon the driving method of the touch panel layer 70.
As described above, the related art liquid crystal display device having a touch panel fixed thereto is configured of a touch panel having a touch function, and a separate lens layer having a lens function for displaying stereoscopic image, each layer having an adhesion layer deposited therebetween. Herein, a considerable number of film adhesion processes and bonding processes is required for each adhesion layer, and a considerable number of plates or glasses that are to be provided to the touch panel and the lens layer is required. Therefore, in manufacturing a display device having such complex functions, a high fabrication cost is required.
As described above, the related art liquid crystal display device having a touch panel fixed thereto has the following disadvantages.
For example, in case of a display device separately configuring a touch panel having a touch function, and a lens layer having a lens function for a stereoscopic image display, an adhesion layer should be provided between each layer. Herein, a considerable number of film adhesion processes and bonding processes are required to be performed on each adhesion layer. Accordingly, a number of plates and glasses should be provided in the touch panel and the lens layer. Thus, the processes for forming the display device having such complex functions results in an increase in manufacturing cost.
Also, even when being provided with a configuration layer having functions other than the lens layer of the above-described example, the same problem may occur due to the layers required in between the adhesion layers.